We manipulate a Bose-Einstein condensate using the optical trap created by the diffraction of a laser beam on a fast ferro-electric liquid crystal spatial light modulator. The modulator acts as a phase grating which can generate arbitrary diffraction patterns and be rapidly reconfigured at rates up to 1 kHz to create smooth, time-varying optical potentials. The flexibility of the device is demonstrated with our experimental results for splitting a Bose-Einstein condensate and independently transporting the separate parts of the atomic cloud.

We propose a method for measuring the temperature of fermionic atoms in an optical lattice potential from the intensity of the scattered light in the far-field diffraction pattern. We consider a single-component gas in a tightly-confined two-dimensional lattice, illuminated by far off-resonant light driving a cycling transition. Our calculations show that thermal correlations of the fermionic atoms generate fluctuations in the intensity of the diffraction pattern of light scattered from the atomic lattice array and that this signal can be accurately detected above the shot noise using a lens to collect photons scattered in a forward direction (with the diffraction maxima blocked). The sensitivity of the thermometer is enhanced by an additional harmonic trapping potential. Ultra-cold atomic gases in optical lattices can constitute almost ideal realizations of Hubbard models [1,2] that are fundamental to strongly-correlated physics. Recent experiments on fermionic atoms in lattices have demonstrated both a superfluid pairing [3] and a Mott insulator [4,5], opening up possibilities for experimental simulation of even more complex strongly-correlated systems, such as antiferromagnetic phases and high-T c superconductivity. Thermal energy is a major control parameter in fermionic lattice systems and characterizing phase diagrams is fundamentally related to the ability to perform accurate temperature measurements.Here we show that the temperature of fermionic atoms in a 2D optical lattice can be accurately determined by measurement of the light scattering from the atoms. The diffraction pattern is insensitive to thermal atomic correlations but blocking the diffraction maxima and collecting light scattered outside the diffraction orders using a lens provides a measurable optical signal that reflects thermal and quantum fluctuations of lattice atoms.The temperature of fermionic atoms in optical-lattice experiments has been deduced indirectly from the temperature of the trapped cloud of atoms before turning up the lattice [4,5], and by detecting double-occupancy in a two-species gas by converting atom pairs into molecules [4,6]. Other temperature measurements detected atomic shot-noise [7] or the sharpness of interference peaks [3] in absorption images after a ballistic expansion. This existing technology provided vital information about temperature but it has limitations, and there is a clear need for new methods; e.g., detecting atomic shot noise proved inconclusive in some superfluid/thermal lattice systems [8] and it was argued that detecting superfluidity from the sharpness of interference peaks can be ambigious as even a thermal gas may show misleadingly sharp peaks [9]. Moreover, a range of phenomena occur below the Néel temperatures [10] of these systems, e.g., antiferromagnetic ordering and superfluid pair hopping, but this requires significantly more cooling than current experLens

We provide an experimental demonstration of a direct fiber-optic link for RF transmission ("radioover-fiber") using a sensitive optical antenna based on a rubidium vapor cell. The scheme relies on measuring the transmission of laser light at an electromagnetically-induced transparency resonance that involves highly-excited Rydberg states. By dressing pairs of Rydberg states using microwave fields that act as local oscillators, we encoded RF signals in the optical frequency domain. The light carrying the information is linked via a virtually lossless optical fiber to a photodetector where the signal is retrieved. We demonstrate a signal bandwidth in excess of 1 MHz limited by the available coupling laser power and atomic optical density. Our sensitive, non-metallic and readily scalable optical antenna for microwaves allows extremely low-levels of optical power (∼ 1 µW) throughput in the fiber-optic link. It offers a promising future platform for emerging wireless network infrastructures.

We report on the implementation of an optical tweezer system for controlled transport of ultracold atoms along a narrow, static confinement channel. The tweezer system is based on high-efficiency acousto-optical deflectors and offers two-dimensional control over beam position. This opens up the possibility for tracking the transport channel when shuttling atomic clouds along the guide, forestalling atom spilling. Multiple clouds can be tracked independently by time-shared tweezer beams addressing individual sites in the channel. The deflectors are controlled using a multichannel direct digital synthesizer, which receives instructions on a sub-microsecond time scale from a field-programmable gate array. Using the tweezer system, we demonstrate sequential binary splitting of an ultracold 87 Rb cloud into 2 5 clouds. Many applications in cold atom quantum technology require control over the positions and momenta of atomic clouds or single atoms. The ability to precisely move clouds of atoms around in space may, for example, unlock their use as probes for sampling surfaces and microscopic structures [1] or for mapping out magnetic fields [2]. Several protocols for quantum information processing rely on deterministic rearrangement and controlled transport of neutral atoms [3], where, e.g., quantum logic gates can be formed through the precise movement of atomic qubits [4]. Transport of atoms also emerges as a crucial step in the everyday operation of contemporary cold atom experiments for the purpose of shuttling atoms to a region of higher vacuum or increased optical access [5][6][7][8].Techniques for confining and manipulating polarizable particles by means of optical dipole forces from far-detuned laser beams have gained interdisciplinary importance after the seminal work of Ashkin, with applications ranging from folding of DNA to single atom trapping [9]. A focused reddetuned laser beam acts as an optical tweezer, trapping atoms at the waist [10]. By actively shifting the laser beam focus axially [6] or by steering the laser beam transversely [4,11], the positions of atoms may be controlled; we note that steering can also be accomplished using blue-detuned light [2,12]. Steerable tweezers have been widely applied, particularly within the field of micro-and biological particles. The figures-of-merit of various approaches are, for example, reviewed in [13]. Devices for tweezer steering include galvo and piezo-deflected mirrors, electro-optic deflectors, acousto-optic deflectors (AODs), as well as spatial light modulators. In the context of micro-and biological particles, manipulation of multiple optical traps was first demonstrated two decades ago using time-averaged confinement * Corresponding author: niels.kjaergaard@otago.ac.nz from a rapidly galvo scanned laser beam [14,15]. Work using AODs [16] for time-averaged confinement quickly followed and was successfully extended to micromanipulation of ultracold atoms in multiplexed discrete traps (up to three) [17] and for "painting" arbitrary potentials [18].In this ...